The present invention relates to the production technology of the CD-ROM-, WORM-, WER-class multi-layered optical discs. More particularly, it refers to the methods of replication of the multi-layered optical discs by using the relief-carrying master-discs produced by the technology similar to the contact lithography, as well as to the relief-carrying master-discs with various wetting properties on their surface and in the micro-cavities (pits and grooves), as well as to the liquid light-sensitive compositions of the informative luminescencing media for implementation of the said methods.
The inventive method has advantages, which enable the production of polychrome discs, and thus increase the information. capacity of the discs a few times (approximately, by the number of times equal to the number of chromatic components utilized in a polychrome disc).
1. N. K. Arter et al., xe2x80x9cOptical Disc Familyxe2x80x9d, IBM Technical Disclosure Bulletin, 30, N2, p.667, 1987.
2. S. Brown, xe2x80x9cThe decade of the CDxe2x80x9d, San Jose Mercury News, p.8, Jan. 9, 1994.
3. Y.Okino et al., xe2x80x9cDevelopments in fabrication of optical discsxe2x80x9d, Optical Disc Technology, p.236, 1982.
4. S. Horigome, xe2x80x9cNovel stamper process for optical discxe2x80x9d, Optical Storage Technology, p.121, 1988.
Multi-layered fluorescent optical discs can find wide use owing to the possibility of reaching high bulk density when recording information on them, as well as of retrieving the information with high contract and signal-to-noise ratio.
For this purpose it is desirable to locate a luminescence-emitting information medium only in the pits of CD-ROM or in the pre-recording grooves of CD-WORM or CD-WER. In the present invention, this problem is resolved by using the photolithography technology, or specific types of original master-discs.
Use of contact photolithography to record elements with the resolution as defined in standards for the polycarbonate-base CD is rather difficult, since it is necessary to provide spaces less than 0.2xcexc between the photomask and disc surfaces. The disc surface has a roughness of the order of few microns; moreover, disc thickness can vary gradually by tens of microns. As a result, it is impossible to press the disc to photomask uniformly all over the surface.
By means of modern lithographic devices with adaptive-optics projectors, it is possible to create the required recording elements, but only not on very large disc surfaces; in addition, the projector optics must be adjusted separately when recording each region, and that requires a lot of time and creates problems with recording at the borders of such regions. Besides, these devices are very expensive.